Hepatitis A Among Homosexual Men --
United States, Canada, and Australia

Although male homosexual activity has been reported as a risk
factor for hepatitis A, the frequency with which homosexual
activity was reported by persons with hepatitis A was less than 10%
during 1982-1989 (CDC unpublished data, 1990). However, in June of
1991, CDC received reports from several cities in the United
States, Canada, and Australia of an increase in hepatitis A among
homosexual men during the first 6 months of 1991. This report
summarizes data from each of these cities.

UNITED STATES
Denver

From January through June 1991, 24 cases of hepatitis A were
reported among homosexual and bisexual men in Denver; in
comparison, 0-3 cases were reported during the first 6 months each
of 1986-1990. During the first 6 months of 1991, 59 cases of
hepatitis A were reported among heterosexual adults and children;
although this represents an increase in the number of reported
cases for these groups for the same period over previous years
(1990: 28 cases, 1989: 34 cases, 1988: 23 cases, 1987: 31 cases,
and 1986: 14 cases), the rate of increase is less than that for
homosexual/bisexual men. Of the 24 homosexual/bisexual men with
hepatitis A, 16 lived in one central urban neighborhood. Four
(17%) had commonly recognized risk factors for hepatitis A,
compared with eight (57%) among 14 adult heterosexual men with
hepatitis A.

New York City

From January through June 1991, 631 cases of hepatitis A were
reported in New York City, a 42% increase over the number of cases
reported during the same period in 1990. Most cases (80%) occurred
in Brooklyn (254) and Manhattan (253). In Brooklyn, an ongoing
outbreak of hepatitis A associated with person-to-person
transmission within a traditional ethnic/religious community began
in 1990, with the
number of reported cases remaining relatively stable during the
past 18 months. In contrast, hepatitis A increased more than
fourfold in Manhattan during January-June 1991 over the same period
in 1990 (58).

Of the 253 cases in Manhattan, 221 (87%) occurred among men.
Analysis of the total number of cases by ZIP code of residents
indicated that 115 (45%) patients resided in six ZIP code areas
corresponding to two Manhattan neighborhoods with large homosexual
populations, compared with 17 cases reported from these ZIP code
areas in the first half of 1990. Of 189 persons for whom both age
and sex were known, 154 (81%) were men aged 20-49 years; this is a
5.5-fold increase over the number of cases reported among this
group during the same period in 1990. Race/ethnicity information
was available for 102 (40%) of the 253 cases; 85 (83%) occurred
among white non-Hispanics.

In May 1991, the New York City Department of Health surveyed
50 persons with hepatitis A. Hepatitis A was diagnosed in each
person during January 1-April 15; these persons resided in a
Manhattan neighborhood with a large homosexual male population.
Telephone interviews were completed for 32 (64%) persons.
Twenty-seven (84%) were men; 26 (96%) of these were aged 20-49
years (median: 30 years; range: 22-55 years). Twenty-one (78%) of
the 27 men identified themselves as homosexual or bisexual, three
(11%) as heterosexual, and three (11%) did not state sexual
preference. Male respondents reported a median of one sex partner
(range: 0-7) during the 2-6 weeks before onset of illness. Eleven
(41%) had no risk factors for hepatitis A other than being
homosexual or bisexual. Seven (26%) of the 27 men reported contact
with a person with hepatitis A during their incubation periods; two
of the seven reported sexual contact with a person with hepatitis

These trends continued through the second half of 1991. As of
mid-December, 1116 cases of hepatitis A were reported in New York
City, with 79% occurring in Manhattan (429) and Brooklyn (452). Of
the cases reported from Manhattan, 370 (86%) occurred among men. Of
339 cases for which both age and sex were known, 270 (80%)
occurred among men aged 20-49 years.

San Francisco

From January through November 1991, 350 cases of hepatitis A
were reported to the San Francisco City Department of Public
Health, compared with 254 for the same period in 1990. Of the 350
persons with hepatitis A, 293 (84%) were male, and 186 (78%) of
237 men interviewed identified themselves as homosexual or
bisexual. Of the 254 hepatitis A cases reported in 1990, 189 (74%)
occurred among men, and 64 (68%) of 94 men interviewed identified
themselves as homosexual or bisexual.

CANADA
Toronto

From January through September 1991, 274 cases of hepatitis A
were reported to the City of Toronto Department of Public Health,
representing a fourfold increase over the number of cases reported
during the same period in 1990, when 68 cases were reported (Figure
1). The number of hepatitis A cases reported in Toronto have
increased annually, from 36 in 1985 to 86 in 1990. Of the 274 cases
in 1991, 234 (85%) were among men aged 20-49 years. Risk-factor
information collected on 169 male hepatitis A patients aged 20-49
years in 1991 identified homosexual behavior in 94 (56%) persons,
compared with eight of 37 (22%) for the same period in 1990.

Montreal

From January through mid-November 1991, 389 cases of hepatitis
A were reported in metropolitan Montreal, an incidence rate of 20.7
per 100,000 population; this represents a fourfold increase in the
incidence rate for 1984-1989 of less than 5.0 per 100,000
population. The rate for men was 36.4 per 100,000 compared with 6.3
per 100,000 for women. Two hundred thirty-four (60%) of the cases
were among men aged 20-39 years, and the highest attack rate was
among men aged 25-29 years (82.9 per 100,000).

Among 107 persons with hepatitis A interviewed by telephone
and for whom a risk factor could be identified, 45 (42%) were
homosexual, compared with six (8%) of 72 persons in 1990. No
increases were observed for other possible risk factors.

AUSTRALIA

From January through July 1991, 134 cases of hepatitis A were
reported to the Health Department of Victoria (which includes the
city of Melbourne), compared with 41 cases of hepatitis A reported
for all of 1990, 14 for 1989, 31 for 1988, and 72 for 1987. Of the
cases in 1991, 102 (76%) occurred among men, and 35 (34%) of those
were homosexual.

From January through June 1991, 342 cases of hepatitis A were
reported to the New South Wales Health Department (which includes
the city of Sydney), compared with 34 cases for all of 1990. Of the
326 persons for whom age and sex information were available, 133
(41%) were aged 20-29 years, and 115 (86%) of these were men. Of
the total cases, 131 (38%) were clustered in the eastern suburbs of
Sydney, and 60% of these were identified by telephone interview of
the attending physician as occurring in homosexual men.

Editorial Note

Editorial Note: Hepatitis A virus (HAV) is transmitted by the
fecal-oral route and has traditionally been associated with
crowding, poor personal hygiene, improper sanitation, and
contamination of food or water. The prominent risk factors for HAV
infection include close contact with a hepatitis A patient, travel
to developing countries, contact with children in day care centers,
and intravenous drug use.

Although studies consistently have found an increased
prevalence of hepatitis B virus infection among homosexual men (1),
studies of the prevalence of HAV infection among homosexual men
have shown conflicting results. Studies in New York and Copenhagen
in the late 1970s did not indicate a prevalence of HAV infection
among homosexual men higher than that among matched controls (2,3).
However, a study in Seattle during the same period found a 30%
prevalence of HAV infection among homosexual men, compared with 12%
(p less than 0.01) among heterosexual men (4). A second study
conducted in Copenhagen found a prevalence of HAV infection of 36%
among homosexual men, compared with 20% in heterosexual men (p less
than 0.01) (5). HAV infection among homosexual men was correlated
with an increased number of sex partners, an increased frequency of
oral-anal contact, and multiple episodes of syphilis (4,5).

The age and sex distribution of persons with hepatitis A
reported to CDC's Viral Hepatitis Surveillance Program indicates
that approximately 50% of cases occur among persons 20-39 years of
age, and 15% occur among children aged less than 10 years. The
male-female ratio is generally 1:1. Data presented in this report
indicate a substantial shift in the sex distribution of and risk
factors for hepatitis A in several cities throughout the world.
This is in contrast to recent trends showing a decline in the
incidence of gonorrhea and hepatitis B among homosexual men as a
result of educational efforts targeted at reducing high-risk sexual
behavior (6,7). The increase in hepatitis A among homosexual men
may be a reflection of 1) a population of susceptible homosexual
men who have recently become sexually active with an increase in
the number of sex partners; 2) a return to unsafe sexual practices
that might promote fecal contamination (e.g., oral-anal contact);
and/or 3) misperceptions among the homosexual community regarding
the relative safety of certain sexual behaviors in the transmission
of sexually transmitted diseases (STDs) other than human
immunodeficiency virus.

Early recognition of increases in hepatitis A among homosexual
men should prompt public health officials to collect detailed
information concerning behaviors that would place homosexual men at
increased risk for acquiring hepatitis A and to promote behavior
that prevents further spread of the virus. A public education
campaign in Denver to disseminate information about routes of
transmission of HAV, with emphasis on those associated with sexual
activity, was initiated in May 1991. Written material was posted in
areas frequented by homosexuals, and information was communicated
through area media outlets. Although the effectiveness of the
Denver campaign is difficult to assess, hepatitis A patients stated
during subsequent interviews that, as a result of the information
campaign, they recognized early symptoms and sought medical
attention.

In addition to disseminating information on hepatitis A
prevention, educational efforts should continue to be directed
toward changing behaviors that would place homosexual men at risk
of acquiring any STD.

References

Szmuness W, Much M, Prince A, et al. On the role of sexual
behavior in the spread of hepa titis B. Ann Intern Med
1975;83:489-95.

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